Item Type: 1.5W Solar Panel_x000D_Product Material: Polysilicon_x000D_Working Voltage: 4V_x000D_Working Current: 0-250mA_x000D_Battery Type:2 x Rechargeable AA Battery(Delivered Without Battery) 1High Conversion Rate: 1W solar panel is made of high efficiency polysilicon cells, with high conversion rate and high output efficiency. 2Environmental Friendly: DIY solar panel uses green energy solar energy, which can contribute to environmental friendly, environmental protection and energy saving. 3Strong Adaptability: 4V solar panel can adapt to various complex and harsh weather conditions and is very durable. 4High Stability: The solar charging panel has high stability and good durability. Can be used for a long time. 5Lightweight Portable: The solar panel module is lightweight, easy to carry and easy to use.